Liquid spraying device for liquid fuel burners



Patented June 29,

mourn SPRAYING nnvrca Foa mourn FUEL nUaNEas Adolf Bargeboer, The Hague,Netherlands; vested in the 'Alien Property Custodian Application net,1939, Serial No. 278,013

- 1: Claim. (Cl. ass-12o) One object of my invention is to impr ve theefllciency of the heretofore known spraying devices of this type and toprovide an apparatus which produces a very fine and evenly distributedfuel mistcomposed of minute substantially uniform globules which areproduced even when extremely heavy and crude fuels are used.

Another object of my invention is to provide a liquid spraying device ofthe type described which may be easily manufactured and which occupiesvery little space.

In my U. S. Patent No. 2,079,430, there is described a spraying devicein which tangential channels lead to a whirling chamber or space and arearranged at an oblique angle to the axis of said chamber, the latterbeing provided with a small axial spray opening and a larger axialreturn opening to'produce a central cavity in the liquid rotating in thewhirling space, whereby the liquid emerges from said space as a rapidlyrotating thin film which is broken up into a mist at the edge of thespray opening. Inthe embodiment described in my prior patent the innersurface of the rotating liquid assumes substantially the shape of ahollow double cone.

I have found that the results obtained in my prior constructions can beconsiderably improved if the tangential channels are disposedsubstantially at right angles to the axis of the whn'ling space and thespray orifice is beveled to a knife edge.

This arrangement produces a particularly fin dispersion of the liquidfuel, because the fuel is forced into the whirling space in a directionat right angles to the axis thereof without any axial component. Thusthe highly accelerated spiral fuel flow which is set up occurspractically in a plane, The axial movement of the fuel liquid towardsthe spray orifice is brought about solely by the bevel of the latter. Asa result, the rotating fuel film is forced outwardly against the knifeedge of the spray orifice under a very high centrifugal force so thateven very crude and viscous fuel particles arebroken up into anextremely fine mist at this edge. In the device according to the presentinvenion the inner surface of the rotating liquid assumes substantiallythe shape of a hollow cylinder.

Other advantages of the new arrangement are that the spraying device canbe easily manufactured and has a reduced axial length.

The invention is illustratively exemplified in the accompanying drawing,in which Fig. 1 is an axial section through the tip of a spraying deviceaccording to the invention, and Fig. 2 is a front elevational view ofthe element containing the tangential channels.

In the figures, the nozzle body II is provided at its tip with a centralrecess l2 and with an axial bore ii, In the bottom of the recess i2there is a ring groove H. A plurality of fuel supply channels l5extending parallel to the axial bore l3 open into the groove H. Theatomizing tip of the nozzle comprises an inner endpart l6 and an outerend part ll. A sleeve l8 clrcumferentially embraces the two end parts Itand I1 and holds them together. The whole aggregate l6, l1 and II isinserted into the recess l2 of the nozzle and is held in position by anut I! screwed .onto a screw thread provided on thenozzle head.

The inner end part It comprisesa circular metal disc provided with anannular groove 20 of approximately the same diameter as the annulargroove I4 and communicating with the latter through a plurality ofperforations 2|. A cylindrical central whirling space 22 provided in thesurface of the disc i6 communicates with the groove 20 through aplurality of channels 25 extending in a plane at substantially rightangles to the longitudinal axis of the nozzle. The channels 25 aredisposed tangentially to the whirling space 22, that is the productionsof the inner channel walls extend tangentially to the imaginary cylinderbounding the whirling space. The whirling space communicates with theaxial bore i3 of the nozzle by means of an axial bore 24 concentric withthe whirling space 22 and having a diameter smaller than the diameter ofthe latter. The bore 24 constitutes the return opening ofthe whirlingspace.

The outer end part I! of the atomizing tip comprises a metal ringelement 26 having inserted therein and rigidly united therewith a metalcarbide disc 21 of a diameter substantially equal to the inner diameterof theannular groove 20. The metal carbide disc 21 is provided with acentral spray orifice 28 of outwardly decreasing diameter, the smallestdiameter of said opening being substantially less than that of thereturnbore 24. The bevelled wall 29 of the orifice 28 is disposed at anangle of less than relative to the front face of the disc 21 so nseeoorthat the edge of the spiny orifice 2e ls lormecl as e knife edge Elli.

The device operates as lfollows: Fuel is forced through the channels l6,l6 and 28 into the ennuler groove 2E9 forming the fuel supply chamherand from there through the tangential channels 225 into the whirlingspace 22. The fuel rotating in the whirling space is olrlven into a veryreplol splrel motion precticeliy free of any axial component. en thefuel film rctotlne in the whirling space 22 spreads into the orifice 28,the bevelled well 22$ of the letter eiives en axial component to themovement of the fuel suficient to elect the rotating lrom the nozzletip. However, owing to the high speed ro edge at of the sore orifice 28with almost nn= diminished rotary sneer! enrl will thus he urged againstseirl mire with a very high centrifugel force snfilclent /o tree-l; upand finely the combinetlon of a.- nozzle having whirl chamber, fuelsupply channels projecting ten gentlelly of said whirl chember and in enlene at right angles to its axis, a. well extendinget right angles tothe axis of sold whirl chamber and closing the serne at the rear enoltllereel, sold entire rear well being plane except for at single centralreturn orifice provided in said end well, sold return orifice having ediameter smaller than thet of seiol whirl chamber, and e. hollow conicalportion forming the entire front wall of seicl whirl chamber enolterminetlng at its tip in a bevelled knife edge spray orifice having e,smaller diameter then return orifice.

